Sanding Block for Manual Use, and System Comprising a Sanding Block and an Abrasive Article

ABSTRACT

The disclosure relates to a sanding block for manual use, in particular for manually sanding surfaces, having at least one base plate for holding an abrasive article and at least one sanding block body having a gripping region. According to the disclosure, a rechargeable-battery operated device for removing sanding dust by suction is integrated in the sanding block, said device comprising at least a dust box, a motor housing, in which a drive motor provided with an impeller is provided, and a rechargeable battery for supplying the drive motor with power without an external power supply.

The invention relates to a sanding block for manual use, in particularfor manually sanding surfaces.

PRIOR ART

Sanding is known as a surface treatment for products or objects invarious industrial sectors, such as carpentry and the automotiveindustry. Sanding can be used for various purposes, such as polishing,smoothing, shaping surfaces, repairs, or for special applications suchas removing a layer of paint or surface-grinding a filler from a carbody.

Sanding tools are characterized fundamentally by the presence of anabrasive surface that is designed to act abrasively and provided withabrasive materials, and that is brought into contact with the surface tobe worked and from which material is then removed. This may be donemanually or mechanically. Furthermore, a tool for manual sanding usuallyhas a surface for gripping the tool.

There are already known, for example from EP 11182793 A1, sanding blocksthat are intended for manual use, in particular for manual sanding ofsurfaces, and which have at least one base plate for holding an abrasivearticle, and at least one sanding block body that has a grip region. Itis also known that sanding blocks can be designed in such a manner thatthey are compatible with standard 150 mm sanding discs, which areactually designed for random-orbit sanders, and can therefore be usedfor manual sanding.

DISCLOSURE OF THE INVENTION

The invention is based on a sanding block for manual use, in particularfor manually sanding surfaces, having at least one base plate forholding an abrasive article, and at least one sanding block body havinga grip region. According to the invention, integrated into the sandingblock is an accumulator-battery-operated means for suctioning-offsanding dust, which comprises at least one dust box, a motor housing, inwhich there is provided a drive motor having an impeller wheel, and anaccumulator battery for mains-independent supply of electric power tothe drive motor.

A sanding block is used for manual application, in particular for manualsanding of surfaces. The sanding block differs from orbital andrandom-orbit sanders, where automated or motorized sanding is realizedby use of a motor, by which a base plate, which is mounted so as to bemovable in relation to the orbital and orbital sander, is motor-driven.In the context of this document, therefore, a sanding block isexplicitly to be understood as not having a motor for motorizedexecution of the sanding process. In this sense, the sanding block isused for manual application and manual sanding. The sanding block has asanding block body that, in an embodiment of the sanding block, may berealized as a housing of the sanding block. The sanding block body alsohas a grip region. The grip region enables a user to grip the sandingblock firmly in order to be able to guide it in a controlled mannerduring the execution of a manual sanding motion, in particular over aworkpiece. In an embodiment of the sanding block, the grip region may bedesigned as a handle. Alternatively or additionally, the grip region maybe at least partially rubberized to increase its grip.

A base plate of the sanding block serves to hold and fasten an abrasivearticle to the sanding block, in particular during execution of thesanding process. The base plate is preferably realized as a part of thesanding block body, being integral with it. The base plate is designedto receive an abrasive article, or may itself have at least one abrasivesurface, comparable to a metal plane. In an embodiment of the sandingblock, the base plate constitutes a substantially flat surface. In anembodiment of the sanding block, the base plate has a layer of materialsuitable for realizing a hook-and-loop connection, for example a layerof loops or a layer of flexible barbs.

An accumulator-battery-operated means for suctioning-off sanding dust isprovided, integrated in the sanding block, i.e. arranged in or on thesanding block body and/or at least partly integrated into the sandingblock body. The accumulator-battery-operated means for suctioning servesto suction-off sanding dust produced during a sanding process by manualapplication of the sanding block. For this purpose, theaccumulator-battery-operated means for suctioning comprises at least onedust box, a motor housing, in which a drive motor having an impellerwheel is provided, and an accumulator battery for mains-independentsupply of electric power to the drive motor. In this way, by use of theaccumulator-battery-operated suctioning means, sanding dust producedduring a sanding process can be suctioned-off the surface to be workedand collected in the dust box in a particularly efficient manner.

The drive motor, at least when having been switched on, is supplied withenergy by an accumulator battery for mains-independent supply ofelectric power. In the context of this application, an accumulatorbattery is to be understood to mean an accumulator battery pack,consisting of at least one electrochemical accumulator-battery cell,which supplies an electrical energy. The accumulator batteryconstitutes, in particular, a rechargeable secondary battery that, whenconnected to a charging station, can be recharged. Suitable for energysupply, for example, are accumulator batteries having a cell chemistrythat provides a high power density and/or energy density such as, forexample, accumulator batteries having lithium and lithium-ion cellchemistry, in particular lithium-iron-phosphate, lithium-manganeseoxide, lithium-nickel-cobalt manganese oxide, superlithiatedlithium-nickel-cobalt manganese oxide, lithium-sulfur, lithium-polymerand lithium-oxygen accumulator batteries.

In this way it is possible to specify an autonomous sanding block thatis independent of the mains power supply, i.e. in particular cordless,but that still has means for suctioning-off sanding dust. The sandingblock thus constitutes a particularly handy tool that is always readyfor use, and that can be used or applied in a clean environment since,owing to the accumulator-battery-operated suctioning means, the risk offlying dust and, in particular, the risk of contamination of theenvironment are minimized. Furthermore, owing to the integratedaccumulator-battery-operated suctioning means, there is no need for anexternal suctioning means in addition to the sanding block. Inparticular, it is thereby possible to dispense with an external vacuumcleaner and/or a hose connection from an external vacuum cleaner to thesanding block, which greatly impedes the use of the sanding block duringa manual sanding motion.

Furthermore, owing to the integration of theaccumulator-battery-operated suctioning means, the weight of the sandingblock can advantageously be increased and balanced in such a manner thatthe sanding block lies very well in the hand of the user during asanding process, i.e. during a manual sanding motion.

In an embodiment of the sanding block, the dust box can be detachablyfixed to the motor housing and can be removed from the sanding blockfrom the outside. In this way, it is possible to empty the dust boxeasily as soon as it is filled with sanding dust. For this purpose, thedust box can be removed from the sanding block, emptied and then putback into the sanding block, such that it is again detachably fixed tothe motor housing.

In an alternative embodiment, the dust box may also be realized in theform of a flexible dust bag or the like, which can be detachably fixedto the motor housing. This dust bag may be such that it can be stowedinside the sanding block body, or can be fixed to the outside of thesanding block body.

Accordingly, in an alternative or additional embodiment of the sandingblock, the accumulator battery may also be such that it can bedetachably fixed to the sanding block body and can be removed from thesanding block from the outside. In this way, when the accumulatorbattery is discharged it can easily be replaced by another, charged,accumulator battery. In an embodiment of the sanding block, theaccumulator battery and/or the dust box can be received, at leastportionally, in the grip region of the sanding block, in particular in ahandle of the sanding block. In this way, it is possible to specify anarrangement of the removable components of the sanding block that isparticularly accessible to the user, such that the accumulator batterycan be easily replaced or the dust box can be easily emptied.

In an embodiment of the sanding block, there is a control element, forswitching the drive motor on and off, arranged on an outer surface ofthe sanding block. The control element serves to start and stop thesuctioning. Such a control element may be realized, for example, in theform of a pressure switch, a pushbutton, a slide switch, or the like. Inparticular, the control element is arranged on the side of the sandingblock that faces the user when the sanding block is being used.Preferably the control element is arranged in or on the grip region, inparticular in or on the handle, such that it is always accessible to theuser while performing the manual sanding motion.

In an embodiment of the sanding block, realized on the motor housingthere is an air passage opening, to which the dust box can be detachablyfastened, wherein the dust box has at least one further air passageopening, on which a filter medium can be arranged. It is therebypossible to specify an accumulator-battery-operated suctioning meansthat is of a particularly simple structural design but that stilloperates in a particularly efficient manner. The impeller wheel, whichis set in motion by the drive motor, generates an airflow that isdirected into the motor housing from the surface of the workpiece to beworked. The airflow continues through the motor housing and through theair passage opening into the dust box, and dust transported by theairflow is caught in the filter medium when leaving the dust box throughthe other air opening.

In an embodiment of the sanding block, the base plate has at least oneopening for suctioning-off sanding dust, through which dust can besuctioned-off. In particular, the sanding block—in an embodiment thebase plate—has an air guide element for suctioning-off sanding dust,which in particular is connected to the at least one opening and to theaccumulator-battery-operated means for suctioning-off sanding dust. Inthis way, the sanding dust produced during the sanding process can besuctioned-off, directly at the point of origin, from the surface of thework piece to be worked. Contamination of the environment bysuctioning-off of dust not effected directly on the workpiece isavoided.

In an alternative or additional embodiment of the sanding block, thesanding block has a dust suction nozzle, for suctioning-off sandingdust, which is arranged on the outside of the sanding block. The dustsuction nozzle in this case is likewise connected, by use of an airguide element, to the accumulator-battery-operated means forsuctioning-off sanding dust. In this way, because of the design,reliable suctioning-off of dust on the workpiece can be specified. Thedust suction nozzle in this case may be arranged, for example, aroundthe sanding block. Alternatively, the dust suction nozzle may also bearranged on particular sides of the sanding block, for example on thesides of the sanding block in the direction of which the manual sandingmotion is preferably effected during a sanding process.

The invention also relates to a system comprising at least one sandingblock according to the description above, and at least one abrasivearticle that is designed to be connectable to the base plate of thesanding block, wherein the base plate and the abrasive articlerespectively have at least one opening, preferably respectively aplurality of openings, for suctioning-off sanding dust.

The “abrasive article” may be, for example, a coated abrasive article,in particular sandpaper, abrasive foam, abrasive fabric, knittedabrasive fabric, non-woven abrasive fabric, or the like. Furthermore, inprinciple, bonded abrasive articles are also conceivable, such astypically resin-bonded abrasive cut-off and roughing disks. The abrasivearticle may exist, in particular, in differing product forms, forexample as a sanding disk or sanding strip. In an embodiment of thesystem, one opening of the base plate and one opening of the abrasivearticle, in particular the plurality of openings of the base plate andthe plurality of openings of the abrasive article, are substantiallycongruent in a state in which the abrasive article has been connectedthe base plate of the sanding block.

DRAWINGS

The invention is explained in greater detail in the followingdescription on the basis of exemplary embodiments represented in thedrawings. The drawings, the description and the claims contain numerousfeatures in combination. Persons skilled in the art will expedientlyalso consider them individually and combine them to form appropriatefurther combinations. In the figures, elements that are the same aredenoted by the same references.

There are shown:

FIG. 1 a perspective view of an exemplary embodiment of the sandingblock according to the invention;

FIG. 2 a schematic sectional representation of the embodiment of thesanding block according to the invention of FIG. 1;

FIG. 3 a schematic sectional representation of an embodiment of analternative sanding block according to the invention.

FIG. 1 shows a perspective view of a sanding block 10 according to theinvention. The sanding block 10 for manual application, in particularfor manually sanding surfaces (not represented here in greater detail),has a base plate 12 for holding an abrasive article 14. The abrasivearticle 14 is arranged on the base plate 12 by means of a hook-and-loopfastener, both the base plate 12 and the abrasive article 14 each havinga complementary layer of material 16, in particular a layer of loops anda layer of flexible barbs, suitable for realizing a hook-and-loopconnection.

The layer of material 16 suitable for realizing the hook-and-loopconnection is in this case located at least on the underside, inparticular at least also on the side faces, of the base plate 12. Thebase plate in this case is shaped, in particular, in such a manner thatit realizes at least one right-angled corner, and quite particularlyrealizes two or four right-angled corners. By use of these right-angledcorners, a workpiece can also be sanded or polished well into corners.In order to make the sanding block 10 also compatible with roundabrasive articles, such as those commonly commercially available, it isprovided that the layer of material 16 is also arranged on the sidefaces of the base plate 12. In this way, the circular segments of theround abrasive articles 14 that project from the underside (sandingside) of the base plate 12 can be folded up and fastened to the layer ofmaterial, while at the same time the right-angled corners of theunderside of the base plate 12 are covered with abrasive article 14. Thedimensions of the base plate 12 in this case are selected, by way ofexample, in such a manner that a 150 mm abrasive article 14 can befastened to the base plate 12 without wrinkles, and the projectingcircle segments can also be folded over onto the side faces of the baseplate 12 without wrinkles.

The sanding block 10 has a sanding block body 18 having a grip region20, the grip region 20 in this case being shaped in the form of a knob(convex) and thus conforming particularly smoothly to the handsurrounding the grip region. The surface of the grip region 20 may berubberized (not represented in greater detail here).

The sanding block body 18 at least substantially encloses, as a type ofhousing, the components of the sanding block that are necessary and/orexpedient for the realization of an accumulator battery-operated means22, integrated into the sanding block 10, for suctioning-off sandingdust, see FIG. 2. Provided between the grip region 20 and the base plate12 is an accumulator battery holder 24, which projects, in particularaxially, into the sanding block body 18. The accumulator batteryreceiver 24 serves to reversibly receive an accumulator battery 26, seeFIG. 2.

FIG. 2 shows a schematic sectional representation of the embodiment ofthe sanding block 10 according to the invention from FIG. 1, togetherwith the sanding block body 18 having the grip region 20, the base plate12, and the accumulator battery holder 24, in which, in the exemplaryembodiment represented, there is an inserted accumulator battery 26. Theaccumulator battery 26 serves to supply energy to theaccumulator-battery-operated means 22 for the suctioning-off of sandingdust. For the purpose of recharging the accumulator battery 26 orexchanging it for another accumulator battery 26, the accumulatorbattery 26 can be reversibly removed from the sanding block 10 from theoutside, as it is detachably fixed to the sanding block body 18. Theaccumulator battery 26 engages, for example, only portionally in thesanding block body 18 and can therefore be received at least portionallyin the grip region 20 of the sanding block 10. In particular, theaccumulator battery 34 is realized in the manner of an exchangeablebattery and is detachably fastened, e.g. latched, to the sanding blockbody 18. The accumulator battery 26 has, for example, a nominal voltageof 10.8 V with an available charge of 1.3 Ah, 1.5 Ah, 2.0 Ah or 4 Ah. Tomonitor a corresponding state of charge of the accumulator battery 34,the sanding block 10 may optionally have a charge-state indicator (notrepresented in greater detail here).

Provided inside the sanding block 10, in particular inside the sandingblock body 18, there is also a dust box 28 and a motor housing 30. Thedust box 28 can be detachably fixed to the motor housing 30. Arranged inthe motor housing 30 are at least one impeller wheel 32 and a drivemotor 34, the impeller wheel 32 being connected to the drive motor 34 ina rotationally movable manner, in particular so as to be movable about acentral axis of rotation (rotation shaft). The impeller wheel 32 has aplurality of ribs (“blades”, not represented in greater detail here),which are inclined in the direction of the axis of rotation and which,upon rotation of the impeller wheel 32, accelerate air from a regionclose to the axis of rotation to a radially distant region (see arrowsin FIG. 2). The drive motor 34, when in operation, is supplied withmains-independent electric power by the accumulator battery 26.

Arranged on a side of the grip region 20 that faces toward the user,i.e. on an outer face of the sanding block 10, there is a controlelement 36 for switching the drive motor 34 on and off. In thisexemplary embodiment, the control element 36 is realized as a capacitiveswitch, which detects the presence of a hand on the grip region and,after a defined dwell time of the hand, enables the supply of power tothe drive motor 34. For this purpose, the accumulator battery 34 isconnected in an electrically conductive manner, via contact elements, toan electronics unit (not represented in greater detail here) that isarranged inside the motor housing 30 and connected to the controlelement 36 for switching the drive motor 34 on and off. The electronicsunit in this case is designed at least for switching the drive motor 34on and off upon a corresponding actuation of the operating element 36,and for controlling the drive motor 34.

As an illustration, the motor housing 30 and the dust box 28 realize avacuum-cleaner housing, which has air passage openings 38 on both themotor housing 30 and the dust box 28. In the exemplary embodimentrepresented, the dust box 28 is at this point (interface) detachablyconnected or connectable to the motor housing 30, in particular fixed toit. Arranged in the region of these air passage openings 38, preferablybetween the dust box 28 and the motor housing 30, is a viscoelasticseal, in particular a ring-shaped rubber sleeve (not represented ingreater detail here), at least to seal the motor housing 30 and the dustbox 28. This seal is preferably designed to fix a disposable filtermedium 40 and/or a filter holder carrying the disposable filter medium40 to the motor housing 30 in an airtight manner, in particular to lockit in place. This disposable filter medium 40 serves to allow an airflowfrom the motor housing 30 into the dust box 28 (“permeable to airflow”),but to prevent an airflow in the opposite direction, i.e. backflow. Inthis way, it is ensured that dust 42 already in the dust box 28 cannotreturn to the motor housing 30.

The dust box 28 is designed in such a manner that one side of the dustbox 28 is realized as part of the surface 44 of the sanding block body18. In this way, the dust box 28 can be received, at least portionally,in the grip region 20 of the sanding block 10. Furthermore, in this waythe dust box 28 is detachably fixed to the motor housing 30 and can beremoved from the sanding block 10 from the outside. For this purpose,arranged in the region between the control element 36 and the dust box28, preferably also on a side of the sanding block 10 that faces towardthe user, there is preferably a spring-loaded actuating element 46 thatcan be actuated to release the dust box 28 fixed to the motor housing30. If the dust box 28 is filled with dust 42, it can be removed fromthe sanding block body 18, emptied and then reinserted in a particularlysimple manner. In the side of the dust box 28 that is realized as thesurface 44 of the sanding block body 18 there are openings, which alsoserve as air passage openings 38 and which are preferably at leastpartially covered by a, in particular fine, filter medium 48. For thispurpose, a filter holder (not represented in greater detail here) thatcarries the filter medium 48 may be fixed in an airtight manner, inparticular latched in place, inside the dust box 28. In this way, an airpassage opening 38, to which the dust box 28 is detachably fixed, isrealized on the motor housing 30, the dust box 28 having at least onefurther air passage opening 38, at which a, in particular fine, filtermedium 48 can be or is arranged.

A deflection means 50 is arranged in the motor housing 30, facing theairflow opening 38, the deflection means 50 preferably being alignedobliquely in relation to the axis of rotation of the impeller wheel 32.Realized on the motor housing 30, in the region of the axis of rotationof the impeller wheel 32, there is an air guide element 52, which isdesigned to guide an airflow (arrows in FIG. 2) from the base plate 12in the direction of the region of the impeller wheel 32 close to theaxis of rotation. In particular, an airflow in this direction isinitiated because of the rotary motion of the impeller wheel 32 (suctioneffect of the impeller wheel 32).

In the section of the exemplary embodiment represented in FIG. 2, thebase plate 12 of sanding block 10 has 8 visible, i.e. represented,openings 54 for suctioning-off sanding dust. The openings 54 in the baseplate 12 are connected to the motor housing 30 via a duct system 56inside the base plate 12, which also constitutes an air guide element52, and via the air guide element 52. In this way, the air guide element52, which in particular is connected to the openings 54 and to theaccumulator-battery-operated means 22 for suctioning-off sanding dust,is designed to suction-off sanding dust.

FIG. 2 furthermore shows a system comprising at least one sanding block10 and at least one abrasive article 14 that is connected to the baseplate 12 of the sanding block 10, the base plate 12 and the abrasivearticle 14 respectively having at least one opening 54, preferablyrespectively a plurality of openings 54, for suctioning-off sandingdust. The plurality of openings 54 in the base plate 12 and theplurality of openings 54 of the abrasive article 14 are substantiallycongruent (coincide with one another such that air passage is possible)in a state in which the abrasive article 14 has been connected to thebase plate 12 of the sanding block 10.

In an alternative embodiment of sanding block 10, as represented in FIG.3, a dust suction nozzle 58, for suctioning-off sanding dust, isarranged on the outside of sanding block 10, in particular on theoutside of base plate 12. In this exemplary embodiment, no openings 54in the abrasive article 14 and in the base plate 12 are necessary toobtain the suctioning-off effect.

During the operation of the drive motor 34, a generated negativepressure causes an airflow (arrows) to be generated, through theopenings 54 or through the dust suction nozzle 58 along the air guideelement 52 into the motor housing 30, which carries along dust 42,occurring on the workpiece surface, into the dust box 28. The airflowenters the dust box 28 via the deflection means 50. There, the airflowexits the sanding block 10, via the filter medium 48, as a cleanedairflow, and the dust 42 remains in the dust box 28.

1. A sanding block for manually sanding surfaces, comprising: at leastone base plate configured to hold an abrasive article; at least onesanding block body having a grip region; and anaccumulator-battery-operated mechanism configured to suction-off sandingdust, wherein the accumulator-battery-operated mechanism includes (i) atleast one dust box, (ii) a motor housing, in which there is provided adrive motor having an impeller wheel, and (iii) an accumulator batteryconfigured to supply electric power to the drive motor.
 2. The sandingblock as claimed in claim 1, wherein the dust box is configured to bedetachably fixed to the motor housing and removed from the sanding blockfrom the outside.
 3. The sanding block as claimed in claim 1, whereinthe accumulator battery is configured to be detachably fixed to thesanding block body and removed from the sanding block from the outside.4. The sanding block as claimed in claim 1, wherein the accumulatorbattery and/or the dust box is configured to be received, at leastpartially, in the grip region of the sanding block.
 5. The sanding blockas claimed in claim 1, further comprising a control element configuredto switch the drive motor on and off, wherein the control element isarranged on an outer surface of the sanding block.
 6. The sanding blockas claimed in claim 1, wherein: the dust box is detachably fastened tothe motor housing, a first air passage opening is defined in the motorhousing, the dust box has at least one second air passage opening, and afilter medium is supported on the dust box so that air passing throughthe at least one second air passage opening is caused to pass throughthe filter medium.
 7. The sanding block as claimed in claim 1, whereinthe base plate has at least one opening configured to suction-offsanding dust.
 8. The sanding block as claimed in claim 7, wherein thebase plate has an air guide element configured to suction-off sandingdust.
 9. The sanding block as claimed in claim 1, further comprising adust suction nozzle configured to suction-off sanding dust, wherein: thedust suction nozzle is arranged on the outside of the sanding block, andthe dust suction nozzle is connected, by an air guide element, to theaccumulator-battery-operated mechanism for suctioning-off sanding dust.10. A system comprising: at least one sanding block as claimed in claim1, and at least one abrasive article that is designed to be connectableto the base plate of the sanding block, wherein: the base plate and theabrasive article respectively have at least one opening forsuctioning-off sanding dust.
 11. The system as claimed in claim 10,wherein the at least one opening of the base plate and the at least oneopening of the abrasive article are substantially congruent in a statein which the abrasive article has been connected the base plate of thesanding block.
 12. The sanding block as claimed in claim 4, wherein theaccumulator battery and/or the dust box is configured to be received ina handle of the sanding block.
 13. The sanding block as claimed in claim8, wherein the air guide element is in fluid communication with both theat least one opening and the accumulator-battery-operated mechanism.